Porphyrin derivatives inhibit tumor necrosis factor α-induced gene expression and reduce the expression and increase the cross-linked forms of cellular components of the nuclear factor κB signaling pathway.

The transcription factor nuclear factor κB (NF-κB) is activated by proinflammatory cytokines, such as tumor necrosis factor α (TNF-α) and Toll-like receptor (TLR) ligands. Screening of NPDepo chemical libraries identified porphyrin derivatives as anti-inflammatory compounds that strongly inhibited the up-regulation of intercellular adhesion molecule-1 (ICAM-1) expression induced by TNF-α, interleukin-1α, the TLR3 ligand, and TLR4 ligand in human umbilical vein endothelial cells. In the present study, the mechanisms of action of porphyrin derivatives were further elucidated using human lung adenocarcinoma A549 cells. Porphyrin derivatives, i.e., dimethyl-2,7,12,18-tetramethyl-3,8-di(1-methoxyethyl)-21H,23H-porphine-13,17-dipropionate (1) and pheophorbide a (2), inhibited TNF-α-induced ICAM-1 expression and decreased the TNF-α-induced transcription of ICAM-1, vascular cell adhesion molecule-1, and E-selectin genes. 1 and 2 reduced the expression of the NF-κB subunit RelA protein for 1 h, which was not rescued by the inhibition of proteasome- and lysosome-dependent protein degradation. In addition, 1 and 2 decreased the expression of multiple components of the TNF receptor 1 complex, and this was accompanied by the appearance of their cross-linked forms. As common components of the NF-κB signaling pathway, 1 and 2 also cross-linked the α, ß, and γ subunits of the inhibitor of NF-κB kinase complex and the NF-κB subunits RelA and p50. Cellular protein synthesis was prevented by 2, but not by 1. Therefore, the present results indicate that porphyrin derivative 1 reduced the expression and increased the cross-linked forms of cellular components required for the NF-κB signaling pathway without affecting global protein synthesis.

Amiodarone inhibits the Toll-like receptor 3-mediated nuclear factor κB signaling pathway by blocking organelle acidification.

Toll-like receptor (TLR) agonists or pro-inflammatory cytokines converge to activate the nuclear factor κB (NF-κB) signaling pathway, which provokes inflammatory responses. In the present study, we identified amiodarone hydrochloride as a selective inhibitor of the TLR3-mediated NF-κB signaling pathway by screening the RIKEN NPDepo Chemical Library. In human umbilical vein endothelial cells (HUVEC), amiodarone selectively inhibited the expression of intercellular adhesion molecule-1 (ICAM-1) induced by polyinosinic-polycytidylic acid (Poly(I:C)), but not tumor necrosis factor-α, interleukin-1α, or lipopolysaccharide. In response to a Poly(I:C) stimulation, amiodarone at 20 µM reduced the up-regulation of mRNA expression encoding ICAM-1, vascular cell adhesion molecule-1, and E-selectin. The nuclear translocation of the NF-κB subunit RelA was inhibited by amiodarone at 15-20 µM in Poly(I:C)-stimulated HUVEC. Amiodarone diminished the fluorescent dots of LysoTracker® Red DND-99 scattered over the cytoplasm of HUVEC. Therefore, the present study revealed that amiodarone selectively inhibited the TLR3-mediated NF-κB signaling pathway by blocking the acidification of intracellular organelles.

Alantolactone derivatives inhibit the tumor necrosis factor α-induced nuclear factor κB pathway by a different mechanism from alantolactone.

Alantolactone is a eudesmane-type sesquiterpene lactone that exerts various biological effects, including anti-inflammatory activity. In the present study, screening using the RIKEN Natural Products Depository chemical library identified alantolactone derivatives that inhibited the expression of intercellular adhesion molecule-1 (ICAM-1) on human umbilical vein endothelial cells stimulated with proinflammatory cytokines and Toll-like receptor ligands. In human lung adenocarcinoma A549 cells stimulated with tumor necrosis factor-α (TNF-α), six alantolactone derivatives inhibited ICAM-1 expression in a dose-dependent manner and at IC50 values of 13-21 µM, whereas that of alantolactone was 5 µM. Alantolactone possesses an α-methylene-γ-lactone moiety, whereas alantolactone derivatives do not. In the nuclear factor κB (NF-κB) signaling pathway, alantolactone prevented the TNF-α-induced phosphorylation and degradation of the inhibitor of NF-κB α (IκBα) protein, and its downstream signaling pathway. In contrast, alantolactone derivatives neither reduced TNF-α-induced IκBα degradation nor the nuclear translocation of the NF-κB subunit RelA, but inhibited the binding of RelA to the ICAM-1 promoter. The inhibitory activities of alantolactone and alantolactone derivatives were attenuated by glutathione. These results indicate that alantolactone derivatives inhibit the TNF-α-induced NF-κB pathway by a different mechanism from alantolactone.

Efficacy of stylet angulation at the holding position during tracheal intubation with a videolaryngoscope: a randomized controlled trial.

The aim of this randomized controlled trial was to determine the efficacy of stylet angulation at the holding position during tracheal intubation with a McGRATH MAC videolaryngoscope. Patients were randomized to a group for intubation without stylet angulation at the holding position (non-angulation group) and to a group for intubation with stylet angulation at the holding position (angulation group). The primary outcome was the time for placement of the tracheal tube. Sixty patients were analyzed. The mean (standard deviation) times for tube placement were 21.3 (5.6) s in the non-angulation group and 16.9 (3.8) s in the angulation group (P < 0.001). The scores of operator's perception of difficulty in tube delivery, number of attempts for tube delivery, and degrees of extension, abduction, internal rotation of the right upper arm and extension of the right wrist during tube placement in the angulation group were significantly smaller than those in the non-angulation group (P < 0.001, P = 0.002, P < 0.001, P < 0.001, P < 0.001, P < 0.001, respectively). Our results suggest that stylet angulation at the holding position improves maneuverability of the tracheal tube and enables easy, smooth, and swift tube placement during tracheal intubation with a McGRATH MAC videolaryngoscope.

Different localization of lysosomal-associated membrane protein 1 (LAMP1) in mammalian cultured cell lines.

Lysosomal-associated membrane protein 1 (LAMP1) mainly localizes to lysosomes and late endosomes. We herein investigated the intracellular localization of lysosomal membrane proteins in five mammalian cultured cell lines. Rat LAMP1 fused to enhanced green fluorescent protein (EGFP) mostly accumulated at a particular cytoplasmic area and barely co-localized with LysoTracker® Red DND-99 in golden hamster kidney BHK-21 cells and Chinese hamster ovary CHO-K1 cells. Golden hamster, Chinese hamster, and human LAMP1-EGFP showed a similar intracellular distribution to rat LAMP1-EGFP in BHK-21 cells. Endogenous LAMP1 was also detected in a perinuclear area in BHK-21 cells and CHO-K1 cells, and co-localized with rat CD63-EGFP in BHK-21 cells. Moreover, rat LAMP1-DsRed-Monomer co-localized well with the human trans-Golgi network protein 2-EGFP in BHK-21 cells. These results reveal that LAMP1 predominantly localizes to the trans-Golgi network in BHK-21 cells.

Therapeutic Vaccine Against S100A9 (S100 Calcium-Binding Protein A9) Inhibits Thrombosis Without Increasing the Risk of Bleeding in Ischemic Stroke in Mice.

Decreased adherence to daily ingestion of antiplatelet drugs is a critical issue, increasing mortality and morbidity in poststroke patients. As vaccination could be a promising approach to solving this, we designed an antiplatelet vaccine that inhibited S100A9 (S100 calcium-binding protein A9)/CD36 (cluster of differentiation 36) signaling in platelets, which was reported to be a key signal in arterial thrombosis, but not hemostasis. Immunization with this vaccine induced a sustainable increase in the anti-S100A9 antibody titer for >2 months and an additional booster immunization enhanced the antibody production further. The middle cerebral artery occlusion time was successfully prolonged in the vaccinated mice, which was comparable to that in mice treated with clopidogrel. The antithrombotic effect lasted for 84 days after the last vaccination, as well as after the booster immunization. Importantly, the bleeding time was not affected in the immunized mice. The antithrombotic effect was also observed in the common carotid artery, which was similar to that found in CD36-/- mice. Vascular injury increased the expression of S100A9 in the serum and phosphorylation of JNK (c-Jun N-terminal kinase) and VAV1 in the platelets, but these increases were inhibited in the immunized mice. Moreover, the S100A9 vaccine did not induce cell-mediated autoimmunity, as demonstrated by the enzyme-linked immunosorbent spot assay. Thus, immunization with the S100A9 vaccine resulted in long-term inhibition of thrombus formation through inhibition of increased S100A9/CD36 signaling without risk of bleeding or adverse autoimmune responses. Vaccination against S100A9 might be a novel therapy to prevent recurrent ischemic stroke.

Asiatic Acid, Corosolic Acid, and Maslinic Acid Interfere with Intracellular Trafficking and N-Linked Glycosylation of Intercellular Adhesion Molecule-1.

The pentacyclic triterpenoid ursolic acid was previously shown to inhibit the intracellular trafficking of intercellular adhesion molecule-1 (ICAM-1) from the endoplasmic reticulum (ER) to the Golgi apparatus. In the present study, we further investigated the biological activities of three pentacyclic triterpenoids closely related to ursolic acid on the interleukin 1α-induced expression and intracellular trafficking of ICAM-1. In human lung adenocarcinoma A549 cells, asiatic acid, corosolic acid, and maslinic acid interfered with the intracellular transport of ICAM-1 to the cell surface. Endoglycosidase H-sensitive glycans were linked to ICAM-1 in asiatic acid-, corosolic acid-, and maslinic acid-treated cells. Unlike corosolic acid, asiatic acid and maslinic acid increased the amount of the ICAM-1 protein. Moreover, asiatic acid increased the co-localization of ICAM-1 with calnexin (an ER marker), but not GM130 (a cis-Golgi marker). Asiatic acid, corosolic acid, and maslinic acid inhibited yeast α-glucosidase activity, but not Jack bean α-mannosidase activity. These results indicate that asiatic acid, corosolic acid, and maslinic acid interfere with the intracellular transport of ICAM-1 to the cell surface and cause the accumulation of ICAM-1 linked to endoglycosidase H-sensitive glycans.

UR-3216: a new generation oral platelet GPIIb/IIIa antagonist.

Various oral platelet GPIIb/IIIa receptor antagonists have undergone clinical investigations, but to date without success. Various factors have been proposed to explain their failure such as low affinity for the receptor, large peak/trough ratio, low bioavailability, partial agonist activity and pro-aggregatory effect. Efforts to discover a truly effective, safe, oral antagonist led to the discovery of UR-3216 (Fig. 1). The active form of UR-3216, UR-2922, possessed a high affinity for the human platelet receptor (K(d) <1 nM) with a slow dissociation rate (k(off)= 90 min) in vitro. UR-2922 induced no ligand-induced binding sites (LIBS) expression or prothrombotic activity in human platelets, distinctly different from orbofiban and other small molecule antagonists. To date, UR-2922 is the only high affinity GPIIb/IIIa antagonist without LIBS expression. In vivo characteristics of UR-3216 showed prolonged duration of efficacy (>24 h) with its favorable pharmacokinetic profile, superior to all the other oral GPIIb/IIIa antagonists. UR-3216 showed high bioavailability, rapid bioconversion to the active form and biliary excretion. UR-3216 is a novel, orally active GPIIb/IIIa antagonist of a new generation, which has substantially improved the crucial compounding factors and will be useful for the treatment of cardiovascular diseases.